‘The Final Secret of the Universe’?

1.

In his preface to Lonely Hearts of the Cosmos, Dennis Overbye writes:

It is probably part of the human condition that cosmologists (or the shamans of any age) always think they are knocking on eternity’s door, that the final secret of the universe is in reach. It may also be part of the human condition that they are always wrong. Science, inching along by trialand-error and by doubt, is a graveyard of final answers.

George Bernard Shaw expressed a similar idea when, in October 1930, in a speech at a London dinner in honor of Albert Einstein, he noted that Newton had created a universe that lasted for three hundred years before it was superseded by Einstein’s universe based on the general theory of relativity. Shaw supposed that the audience wanted him to say that Einstein’s universe would never stop, but with the wisdom of his cocked eye, he was moved to say, “I don’t know how long it will last.”¹

At the time, Einstein’s general theory of relativity had come to dominate our understanding of space, time, and gravity (as it still does), but there was growing reason to doubt the model of the universe—the cosmology—that Einstein had calculated from it. Einstein’s model assumed that the universe was homogeneous—that its distribution of mass was, on average, the same everywhere—and that it was static, unchanging in its basic structure through time. In 1922, the Russian mathematician Alexander Friedman challenged Einstein’s model on theoretical grounds, contending that the assumption of a static universe was unnecessary and that, without it, the theory of general relativity predicted a universe that was continually expanding.

Neither Einstein’s nor Friedman’s model was based on any astronomical data; both were pencil-and-paper constructions, partly because in the early 1920s very little data bearing on cosmological questions was available. For example, it was uncertain whether giant systems of stars existed beyond the Milky Way galaxy, of which our own sun is a part. Among the types of data that have a bearing on cosmological issues, two were seen as fundamental: the distance and the motion of large groups of stars. Distances to a group could be ascertained by measuring the cycles of brightness and dimness of certain stars called Cepheid variables; and the speeds with which groups moved away from us could be determined by analyzing how far the light emitted by them was shifted toward the red end of the spectrum. During the 1920s efforts to study Cepheids in faint nebulae revealed that the universe contained many separate galaxies—each comprising an enormous number of stars—at vast distances from our own.

The pioneer practitioner of this research was the astronomer Edwin Hubble, who used the new and powerful 100-inch telescope at the Mount Wilson Observatory, high above Los Angeles, not only to map the distances to a number of galaxies but also to measure their red shifts. The accumulated data led Hubble to conclude, in 1929, that other galaxies were moving outward from us in all directions and that the ratio of their speed to their distance from us was a constant (eventually termed Hubble’s constant). Since light travels at a constant speed, the more distant a galaxy, the farther back in time its light reaching us had been emitted. The Hubble relationship thus implied that the earlier in the history of the universe one looked, the closer to each other the galaxies had been. It provided stunning evidence that the universe was, in fact, expanding—not from any one point but, in the Einsteinian manifold of space-time, from all points, uniformly.² It also permitted Hubble to calculate the age of the universe—which he did, arriving at a couple of billion years, a figure that was troubling because it was about half the age of the earth as it had been determined by radioactive dating.

During the 1930s a Belgian physicist and priest named Georges Lemaître popularized the theory of an expansionist universe, proposing that it had originated in the disintegration of some primeval atom—in a Big Bang, to use the term that the English astronomer and physicist Fred Hoyle coined on a BBC broadcast in the early 1950s for theories that posited a primal cosmological explosion. Hoyle’s coinage was derisory. Although the expansionist model had been supported by additional observational data and theoretical work, it dissatisfied Hoyle, and other scientists as well. It rested on the assumption that the laws of physics had been the same in the distant past as they are now, and, by definition, it posited a beginning—the creation of something out of nothing—that defied physical analysis because it was indeterminate and incalculable. As an alternative, Hoyle, with Hermann Bondi and Thomas Gold, devised a model of the universe maintained in a steady state by the continuous creation of matter throughout space to balance the outward motion of galaxies.

Through the early 1960s the Steady State and the Big Bang models were the principal alternative cosmological theories. They did not really compete with each other because neither was tied to an empirical research program that might lead scientists to choose between them. Indeed, theoretical cosmology struck many astronomers as a largely speculative science, and the number of papers published in the field fell dramatically throughout the 1950s. However, astronomers and astrophysicists could learn about the galaxies and nebula—where they were, what they consisted of, how they were structured, what they were doing. While these topics of observational cosmology touched on cosmological theory, they had an intrinsic interest of their own. And there were powerful instruments to learn with, notably the newer radio telescopes, adaptations of wartime microwave technology to the study of the heavens; and the new 200-inch telescope on Palomar Mountain. The Palomar telescope, which belonged to the California Institute of Technology and began to search the heavens shortly after World War II, gathered four times as much light as the 100-inch telescope on Mount Wilson.

After Hubble’s death, in 1953, Allan Sandage, his protégé at Mount Wilson, turned these instruments to his own purposes, taking over the master’s program, which he thought of as a burden to be willingly shouldered. He recalled to Overbye that it was as though “you were appointed to be copy editor to Dante,” adding, “If you were assistant to Dante and then Dante died, and then you had in your possession the whole of the Divine Comedy, what would you do?” Sandage studied more distant galaxies and gained refined knowledge of the properties of known ones, ascertained brightnesses and the makeup of structures, measured distances and red shifts. During the days when the Big Bang theory seemed in doubt, astronomers compiled evidence of the size of the Hubble constant showing that the universe was even larger, and, hence, older, than the Hubble had estimated, older than the earth. Sandage himself remained convinced—if only because of the uniformity of the ages of the oldest stars both nearby and in other galaxies—that the theory was right.

In 1963, drawing on data from both radio detectors and the Palomar optical telescope, his colleague Maarten Schmidt, a member of the astronomy faculty at Cal Tech, identified a hitherto unknown cosmological entity, which came to be called a quasar (for “quasi-stellar radio source”). It was small yet far more luminous and redshifted than anything previously seen, which meant that it was moving at an immense speed, that its light had been emitted at a comparably enormous distance—several billion years—in the past, and that some mysterious process had been at work then to make it so bright in so small a space. More quasars were rapidly found, eventually at distances that drove the age of the universe back to some ten billion years. In 1965, Dennis Sciama and Martin Rees, at Cambridge University, determined that the density of quasars in space increased with distance from the Milky Way. Quasars were primarily a feature of the ancient universe rather than of the recent one, and this implied that the universe was not steady but had changed from one epoch to the next.

All the while, cosmology had continued to fascinate a few theoretical physicists. In 1964, the Princeton physicist Robert Dicke and his student James Peebles calculated the physical consequences that might be detected as the legacy of a Big Bang (unknown to them, they were repeating a line of inquiry pursued by George Gamow and collaborators in the late 1940s). Their theoretical calculations indicated that an explosive fireball would have yielded the relative mass abundance of hydrogen and helium—about 75 percent and 25 percent, respectively. (The heavier elements comprise only a minute fraction of the cosmic mass.) They also predicted that the radiation of the Big Bang would be present throughout the contemporary universe as a low-energy background—equivalent to the radiation emitted by a black body at the extremely low temperature of several degrees Kelvin. In 1964, Arno Penzias and Robert Wilson, two physicists at the Bell Telephone Laboratories in Holmdel, New Jersey, found a persistent hiss in the receiving system of a large microwave horn-antenna that they had constructed to communicate with the new Telstar satellite. Believing that something was wrong with their equipment, they tried for a year to eliminate the fault. Then they learned about the work of Peebles and Dicke and realized that the antenna had been detecting an echo of the birth of the universe. The indubitable demonstration of the echo eventually earned Penzias and Wilson a Nobel Prize.

The elementary particle physicist and Nobel laureate Steven Weinberg later remarked that the most important result of the discovery of the microwave background radiation was “to force us all to take seriously the idea that there was an early universe.”³ Together with the data on hydrogen and helium abundances and the discovery of quasars, this new finding gave the stock of the Big Bang theory an enormous boost, while driving the Steady State theory into receivership. It also showed that cosmology was a field in which physicists could do something, that it “had some contact with reality,” and that it “was a legitimate science,” as Alan Lightman and Roberta Brawer write in their “Introduction to Modern Cosmology,” the splendidly lucid essay that opens Origins.

The introduction forms a prologue to the transcripts of interviews that Lightman, a trained physicist and accomplished writer, conducted with twenty-seven physicists and astrophysicists and edited with the aid of Brawer, who is doing graduate work in the history of cosmology at MIT, where Lightman is a professor. Lightman and Brawer chose the scientists they talked to both for their different ages and specialties and in order to strike a rough balance between observers and theorists. The interviews are exceptionally readable and informative while retaining the flavor of each scientist’s personality and attitudes. The editors have also provided scientific references to points made in the conversations and a technical glossary that is of considerable help to the lay reader.

Lightman encouraged each of the scientists to discuss three topics: their personal experiences and work; their reactions to recent developments in cosmology; and their personal—that is, philosophical or non-scientific—feelings about their subject. The interviews thus have much to say about the larger implications of astrophysics but are less revealing about its actual practice, especially the tenacity required to persuade telescopes, photometers, and spectrographs to yield data about the heavens. We hear little about the battles waged over whether the data—for example, faint images on a photographic plate or weak signals from an electronic detector—are real or merely artifacts of the apparatus; and the struggles to make sense of the numbers.

Dennis Overbye, who describes himself as having been a “cosmological camp follower” for the last five years, pays attention to these practical difficulties of astrophysics. Attending conferences of astrophysicists, dining and climbing mountains with them, he gathered a great deal of information about them, which he presents in vignettes about their quest for the facts and theories of the cosmos. The result is an impressionistic portrait of the recent history of cosmology, and a somewhat over-dramatized version of it, with heroes like Allan Sandage, who told Overbye how it was during the long, freezing night in the observer’s cage at Palomar—“You sit there straddling the pier with your privates nestled up against the cold of the universe.”

History will undoubtedly relegate some of Overbye’s tales to footnotes. Whatever their ultimate fate, they provide an illuminating companion to the interviews in Origins, and vice versa: since both Lightman and his respondents are tough-minded thinkers, they usefully offset Overbye’s tendency to scientific romance. It is hard for Overbye or anyone else to know what will prove to be lastingly significant about recent cosmology; and it is a strength of both books that while they point to the revolutionary strides made by cosmology since the 1960s, they stress that the field has increasingly had to confront intransigent observational facts that strike at its theoretical structure.

2.

A salient feature of cosmology since the 1960s has been the increasing involvement of physicists who had previously not been much concerned with the origins of the universe, especially theorists of the interactions and relationships of elementary particles. Several reasons have been advanced to account for the trend, including a flight from the increasingly Big Science character of the physics that is done with particle accelerators, and a reaction against the reduced funding for particle physics during the 1970s. Yet at least as important was the essential completion by the middle of that decade of an elementary-particle theory that unified electromagnetic forces and those of the so-called weak interactions. In view of the detection of the microwave background radiation, the theory could be respectably applied to speculations about cosmological processes back to the first few minutes of the universe, even to its first tiny fractions of a microsecond.

According to Lightman and Brawer, particle physicists transformed cosmology by bringing “a fresh stock of ideas and a new set of intellectual tools to bear on the question of why the universe has the properties it does, not just what those properties are.” By the end of the 1970s, several of these properties were attracting particular analytical attention. One was that the microwave background radiation was remarkably uniform, with precisely the same features in whatever direction one looked. This fact gave rise to the “horizon problem,” the puzzle that regions of the universe beyond each other’s horizon (that is, too distant to affect each other) had cooled, and had smoothed out their early irregularities to exactly the same extent. Another was that the ratio of photons (particles of light) to baryons (material particles such as neutrons and protons) in the universe had been measured to be about a billion to one, which raised the simple question of why it has that value rather than another.

A third was the “flatness problem,” which was summarized by a term called omega. Omega is the ratio of the observed average density of the universe to the density that would just balance the energy of its outward motion. If omega is more than one, the universe will eventually fall back into itself; if the ratio is less than one, it will expand limitlessly. If it equals one, the overall curvature of cosmic space would be zero: the universe would be flat and would keep expanding but at a decelerating rate, slowing to a condition of maximum entropy, an eventual thermodynamic death. Measures of the omega ratio had put it at roughly two to one hundred, which is to say that observations had found only two hundredths of the mass density necessary to make the universe flat. Scientists might ordinarily count such a figure as close to zero, but rounding down to nought would imply the absurdity that the universe contains no matter. Cosmologists preferred to round up, partly because it was likely that observations with more powerful instruments would eventually reveal a higher mass density, and thus an omega closer to one. The idea that after so many billions of years omega lies within observational reach of one led many cosmologists to suspect that omega is really one now and must have been one at the time of the Big Bang. But, if it had equaled one then, why? Why had the universe begun in such exquisite balance?

At the end of the 1970s, several groups of particle physicists, including Steven Weinberg, pointed out that the photon-baryon ratio might be accounted for by applying to the earliest processes of the universe some of the grand unified theories that seek to unite an account of strong interactions with those of the electromagnetic and weak ones. Lightman and Brawer note that cosmologists were enormously excited that such a mysterious quantity could be calculated at all and that Weinberg’s example further encouraged younger particle theorists to try their hand at cosmology. Already at work in the field was a very young theorist named Alan Guth, who in the early winter of 1980, while a postdoctoral fellow at Stanford University, used one version of the grand unified theories to investigate how the universe might have behaved under certain conditions when it was less than a microsecond old. He discovered, in the course of one exciting night, that it did not merely expand but blew up at an exponential rate—that in an infinitesimal fraction of a microsecond it doubled in size more than one hundred times, creating a universe that, before its expansion rate returned to that of the standard model, grew several hundred orders of magnitude larger than anything observable today.

Guth’s theory—the inflationary theory of the early universe, as he eventually called it—was rich with consequences. It solved the horizon problem, as Overbye explains:

The original speck would be so small that any uneven spots would have already disappeared. It would already be at the same temperature, for example, and any local bumps or wiggles would be ironed out by the enormous expansion factor, like wrinkles on a fat person, so that the resulting space-time would appear as featureless and even as a tennis court.

The inflationary model also solved the flatness problem because any local region would appear as flat as a tennis court, too.

The inflationary model won rapid support among particle physicists; although considerably modified in the 1980s, it has remained the dominant model of the very early universe, partly because it solves several other nagging conundrums, partly because it provides an entry to the early universe that allows many, though not all, of its features to be calculated rather than posited as arbitrary initial conditions. Edwin Turner, an astrophysicist at Princeton University, told Lightman that the inflationary universe is “a model that allows one to do lots of cute calculations,” adding. “It’s a theorists’ gymnasium, so to speak, where one can go, and there are lots of nice problems to do and to be worked out.”

However, what one group of scientists deems to be satisfying studies others see as clever but frustrating exercises. A number of astronomers find alarming the readiness of hundreds of physicists to apply any new idea in particle theory to the very early universe or to interpret any new observation with explanations that may be ingeniously muscular but defy decisive trial. Models of cosmological behavior in the first few minutes of the universe rest on a well-developed physics, but models of its performance up to, say, less than a billionth of a microsecond—the inflationary models—are grounded in the grand unified versions. Grand unified theories cannot be tested directly because they concern behavior at enormous energies, far higher than anything that is likely to be achieved in a laboratory accelerator. (This may be another reason that so many particle theorists have flocked to cosmology. As the theorist David Schramm has said, “The big bang is the poor man’s particle accelerator.”) So far, they also remain untested by direct cosmological observation. Steven Weinberg commented to Lightman that “a sense of unreality” pervades the inflationary work “because we have no experimental handle on the very early universe—nothing like the helium abundance or the microwave background.”

Big Bang theory is currently vexed by big problems precisely because the key features of its standard form are inconsistent with a growing body of astronomical observations. The galaxies are believed to have formed from fluctuations—small lumps of matter—in the gravitational field, a process that should have left some unevenness (hotspots) in the microwave background radiation; yet the background radiation has proved to be smooth within tiny tolerances. Big Bang theory retains Einstein’s original premise that the universe is homogeneous, but in 1986 Margaret Geller, John Huchra, and Valerie de Lapparent at the Smithsonian Astrophysical Observatory detected galaxies spread over the surfaces of bubble-like structures one hundred million light years across and void inside, which suggested an enormous degree of lumpiness in an extensive region of space. Such discoveries have raised the question, a new and deep one for cosmology, of whether the universe is homogeneous on any scale at all.

Inflationary theory may predict an omega of one, but that value has still not been observed. It is true that the existence of additional cosmological matter, which would be necessary for an omega of one, was hypothesized by James Peebles and his Princeton colleague Jeremiah Ostriker and, in 1978, this was confirmed by Vera Rubin and her collaborators through their measurements of rotational motion in a number of galaxies.⁴ However, this matter, known as “dark matter,” is not the normal luminous matter of stars of gases. Its nature is unknown, which has stimulated a great many hypotheses—more theoretical gymnastics, in the opinion of some—about what it might be. Whatever it is, estimates of the total of darkmatter mass in the universe have increased omega by a factor of ten or so, but at two tenths instead of the previous two hundredths, it is still far short of one.

Eric J. Lerner devotes part of his The Big Bang Never Happened to arguing that these distinctions between theory and observation support his title’s contention. Lerner tells us that in 1970 he quit physics graduate school out of dissatisfaction with the mathematical approach of physics—it seemed “sterile and abstract,” especially in particle physics—and became a science writer, eventually returning to physics research. An interest in fusion drew his attention to the dynamics of plasmas, which are gases of charged particles and, as such, conduct electricity and are affected by magnetic fields. His book insists upon the superior merits of a plasma-based theory of the universe, a model proposed by the Nobel laureate Hannes Alfvén and one to whose development Lerner himself has contributed.

In the cosmology of plasmas, there was no Big Bang; there was simply a universe of random hydrogen plasma. Advocates of the theory hold that just as plasmas in the laboratory tend to pinch themselves together into dense, swirling filaments separated by diffuse voids, so the original plasma particles formed themselves into matter, and ultimately into stars, nebula, and galaxies. Lerner says that this model can account for the Hubble expansion, the microwave background, and the abundance of helium.⁵ He prefers it to Big Bang theory because, while explaining these critical observations, it derives from the empirically determined behavior of plasmas, and not from pure theorizing.

Until recently, the plasma universe commanded very little attention among astrophysicists or cosmologists. Undoubtedly most agree that its claims are highly questionable—James Peebles has called them “silly”—not least because it is difficult to see how electrical and magnetic forces in plasmas can suffice to perform the cosmological duties (for example, the formation of galaxies) shouldered by gravitation in Big Bang theory. Lerner argues that Big Bang cosmologists did not want to hear about the plasma alternative, since any challenge to the theory “would threaten the careers of several hundred researchers,” and he suggests that news of it was suppressed by the Big Bang establishment in the media. Recently, the hypothesis of a plasma universe has received something of a hearing among cosmologists, though not yet what Lerner believes it deserves. Indeed, much of his book is devoted to a major polemical purpose—to explain why, despite the problems with Big Bang theory, the commitment to it has been maintained and the plasma universe alternative has been ignored.

Lerner’s explanation is not so much scientific as cultural. He identifies the Big Bang as a descendant of Platonism, the world view of “a cosmos knowable only to the pure reason of the few who then had the right to rule over the many…the world view of the slaveholder.” He considers plasma cosmology a descendant of the Ionian outlook of “the free craftsman and peasant,” which assumed a world knowable by observation, where “thought and work joined together,” and where “knowledge was available to all and therefore power could not be the monopoly of the few.” According to Lerner, since the Middle Ages the Ionian approach had been ascendant, the Platonic one in retreat. But in the twentieth century, Platonism has been taking hold again in the form of Big Bang theory. “Such a cosmic myth arises in periods of social crisis or retreat, and reinforces the separation of thought and action, ruler and ruled. It breeds a fatalistic pessimism that paralyzes society.”

Lerner thus attributes the tenacious and increasing hold of Big Bang theory to the response of Western civilization to the social, political, and economic catastrophes of the twentieth century—to Verdun, Auschwitz, and Hiroshima, to economic slowdowns and depressions. He believes that a loss of faith in social and cultural progress can be linked to the idea of a universe degenerating from a perfect cosmological beginning. It is not surprising to Lerner that the Big Bang theory flourished simultaneously with the predictions of zero growth that were frequent during the 1970s. But he finds “no better example in this century of the interaction of social ideology and cosmology” than Alan Guth’s invention of inflationary theory at the beginning of the 1980s, a decade of speculative boom that rewarded the well-to-do while permitting competitiveness to decline.

But of course people do not feel that they have been given a license to indulge themselves because they know the universe is degenerating to a cold death some billions of years in the future. Lerner’s cultural history is generally unsupportable, everywhere shallow, and often wrong in detail. So is his sociology of science, not least because he does not seem to have taken the trouble to inquire how contemporary cosmologists came to do their work. To cite just one among many possible examples, Guth conceived the inflationary universe from purely technical considerations—the consequences of supercooling in what physicists call the “false vacuum”—not from any sensitivity to the level of Jimmy Carter’s misery index. A major trouble with Lerner’s analysis is that its empirical basis, not only contemporary but historical, is drastically thin, drawn from a severely limited collection of sources. It is, one might say, an exercise in virtually pure theorizing, a deduction from first cultural principles of how science interacts with human society, followed by an extremely selective use of data to show that the model is true.

Still, Lerner’s theoretical beam sweeps so widely that inevitably it catches elephantine features of the cultural landscape, notably, the tendency for cosmology to be used, especially in conservative times, to bolster religious authority. The phenomenon is nothing new in the twentieth century. While in the late nineteenth century science had been interpreted to be at war with religion, in the 1920s, particularly in liberal Protestant discourse, it was reconfigured to be at peace with it. Einstein’s theory of general relativity found one of its most respected popularizers of that day in Arthur S. Eddington, a British cosmologist and devout Quaker, whose widely read Space, Time and Gravitation was dominated by the theme that relativity insisted that physics could describe only the relationship among measurements, not the “nature of things.” Accordingly, scientific knowledge amounted to “an empty shell—a form of symbols,” with the real world beyond its reach, which left considerable room for creative mind and, by clear implication, for soul, spirit, and God. After the development of quantum mechanics, Eddington promptly told his readers that the new theory was “a denial of determinism,” and that one could recognize “a spiritual world alongside the physical.”⁶

The United States had no scientist comparable to Eddington, but it did have Robert A. Millikan, the head of the California Institute of Technology and a Nobel laureate in physics, who throughout the 1920s, from lecture platforms, in the press, and in a number of books, campaigned for the reconciliation of science and religion. A principal figure in cosmic ray research, Millikan called the rays the “birth-cries” of atoms in space—evidence that the Creator was still on the job, because atomic formation involved a continual release of energy, a process that would save the universe from the heat death to which the second law of thermodynamics had apparently doomed it.⁷

During the last fifteen years, a great many books and articles have appeared drawing religious implications from Big Bang theory. These works have been written by popularizers (largely scientists or science writers), cultural commentators, and some theologians, and they have been published by trade, academic, and ecclesiastical houses, including the Vatican. (As early as 1951, Pope Pius XII, in an address to the Pontifical Academy of Sciences, read contemporary cosmology to mean that “true science to an ever-increasing degree discovers God as though God were waiting behind each closed door opened by science.” ⁸ ) Some of them defend traditional, particularly Christian, religion; others seek satisfaction in a kind of cosmological theism. Overbye pursued the cosmologist Stephen Hawking, searcher after quantum gravity and theorist of black-hole singularities, to put to him a question:

The singularity theorems, to me, were like evidence of a miracle, of a magic outside of physics itself. I wanted to know from Hawking if such miracles, such singular terrible transformations were real. If we couldn’t see God, could we at least know God was there, even if sulking in a black hole or at the end of time? What I wanted from Hawking was some touch of the miraculous.

Which, of course, Hawking declined to give him.

In Genesis and the Big Bang the physicist and theologian Gerald L. Schroeder has no such reluctance. He purports to demonstrate through textual exegesis that the first six days in the biblical and the Big Bang stories are “identical realities…described in vastly different terms“—for example, that inflation is the “wind of God” that moved over the water and that the separation of matter from photons in the early universe correlates with God’s injunction, “Let there be light.” Schroeder adds, “A Big Bang followed by an unending expansion of the universe tells us that there was a beginning and that, at the minimum, there is a place for a Beginner.”⁹

However, many of these writings make no literalist or sectarian commitments. Or even creationist ones: in God and the New Physics, the British physicist and popularizer Paul Davies takes aim at the cosmotheological argument that while everything requires a cause, God does not:

If one is prepared to concede that something—God—can exist without an external cause, why go that far along the chain? Why can’t the universe exist without an external cause? Does it require any greater suspension of disbelief to suppose that the universe causes itself than to suppose that God causes himself?¹⁰

Yet Davies’s book is not a tract against theistic faith. It is rather an exploration of the idea that, as he puts it, “science offers a surer path to God than religion.”¹¹

Writers like Davies can be seen as part of a revival of the tradition of natural theology that has sought to discern the mind and hand of God in the workings of nature. The tradition was discredited during the Darwinian wars of the late nineteenth century; in a sense, the declamations of Millikan in the 1920s, at the time of the Scopes trial, were an attempt at reawakening it. John Polkinghorne, once a physicist and now an Anglican priest, welcomes the revival of natural theology while noting that it has occurred “not so much at the hands of theologians (whose nerve, with some honorable exceptions, has not yet returned) but at the hands of scientists.”¹² Few theologians today would talk like John Updike’s upstart computer hacker, Dale Kohler, in Roger’s Version, when he challenges the divinity teacher Roger Lambert:

“Dr. Lambert, aren’t you excited by what I’ve been trying to describe? God is breaking through. They’ve been scraping away at physical reality all these centuries, and now the layer of the little left we don’t understand is so fine God’s face is staring right out at us.”¹³

It is no surprise that the mirror of cosmological physics reflects whatever religious or philosophical image the beholder wishes to see in it. The illusion is by no means confined to Westerners. Devotees of Eastern mysticism find much in the traditions they are studying that seems to fit with modern physics or cosmology, and several remarkably popular books have been published on the seeming parallels.¹⁴ (Many of the devotees write letters about the scientific suggestiveness of their beliefs to Stephen Hawking, who sharply told Overbye that Eastern mysticism “fails abysmally” as a description of reality because it fails to predict results.) But how is the cosmologist’s description of reality constructed and what part do philosophical or religious conceptions have in it? Lightman’s interviews supply considerable information on this broad subject.

A touchstone for the religious part of the question is the attitudes that prevail among cosmologists toward what is known as the “anthropic principle.” This principle takes two forms—the “weak” and the “strong.” The weak version, which is widely accepted, deals with the fact that, according to a calculation made by the physicist Paul Dirac in 1938, certain fundamental constants (such as the ratio of the electron and proton masses) can be mathematically manipulated so they combine to equal the age of the universe. The weak principle explains that it is only at this epoch of cosmic evolution that conditions—the presence of stars and planets and the heavier elements, for example—happen to allow human beings to exist and thus to be around to observe the constants. The strong version holds that only in a universe with the physical constants of our universe could life as we know it have emerged at all and that, hence, it has these constants in order to allow human existence. For some scientists, the strong anthropic principle explains why the fundamental constants are what they are. But as an explanation it is merely an updated rendition of the old religious argument that the universe is a product of design and that the Designer made it for man.¹⁵

Most cosmologists recognize the strong anthropic principle for what it is and scoff at it (“The anthropic principle is something that people do if they can’t think of anything better to do,” Guth says). Several suggest that it is truly arrogant of human beings to think that they are the central point of the universe and the concern of God. Some say that cosmological knowledge and theory by themselves are enough to teach human beings a lesson in humility. According to inflationary theory, our part of the universe is minuscule. Our universe—according to some interpretations of quantum theory—is only one of many possible universes anyway. And according to the quantum gravitational theories advanced by Hawking and others, none of them necessarily required a creator to get going. They simply arose from random quantum fluctuations. James Gunn, a professor of astrophysics at Princeton University, remarked to Lightman that contemporary cosmology expresses kind of an “ultimate Copernican idea, that not only are we of no conceivable consequence, but even our universe is of no conceivable consequence,” adding, “That’s very pretty.”

Gunn finds that “a lot of people who work in cosmology have…basically religious beliefs,” but as Lightman’s interviews reveal, the beliefs are for the most part like Einstein’s—a faith that the universe is governed by discoverable laws in which a God-like mystery inheres. Among the most thoughtful reflections on the point in Origins is that of Charles Misner, a specialist in general relativity who was raised as a Catholic and has written on issues in science and philosophy:

I do see the design of the universe as essentially a religious question. That is, one should have some kind of respect and awe for the whole business…. It’s very magnificent and shouldn’t be taken for granted. In fact, I believe that is why Einstein had so little use for organized religion, although he strikes me as a basically very religious man. He must have looked at what the preachers said about God and felt that they were blaspheming. He had seen much more majesty than they had ever imagined, and they were just not talking about the real thing. My guess is that he simply felt the religions he’d run across did not have proper respect, or proper dignity, for the Author of the universe.

Yet whether cosmologists wish to eliminate God from any role in creation itself or apprehend God through the mysterious beauty of physical laws, virtually all undoubtedly agree with Allan Sandage that “you cannot do science in a mystical way, but only in a rationalist, reductionist fashion.” Sandage himself recently told the reporter John Noble Wilford that he attributes to God the miracle of existence—that there is something instead of nothing—and the appearance of orderliness in the universe. But he was quick to add, “None of this feeds back at all in to the hard-nosed business of the laboratory or the observatory. It must not.”¹⁶

And evidently it does not, if we are to judge by the attitudes that Lightman and Overbye found in the cosmological camp. Some theorists declare an aesthetic preference for omega’s equaling one. They talk about criteria of elegance and beauty in the formulations of cosmological models. But what their conversation concerns most is whether the evidence supports the models. On the one hand, they reflect on the empirical difficulties that the Big Bang hypothesis has encountered during the last fifteen years; on the other, they stress that during the same period any number of really telling empirical challenges to the standard theory—for example, a lack of helium abundance in some region—might have been detected but have not been.

On the whole, they maintain a basic, rough belief in the modified Big Bang theory for reasons of good scientific practice. Weinberg says that

Scientific practice is not really in danger from a false consensus. It needs a consensus, in order for us to have something to talk about with each other, in order that our work adds up. Without a consensus, you don’t have any way of knowing even if the consensus is wrong.

The idea that science proceeds entirely by Baconian empiricism, that understanding of nature arises wholly by inference from a gathering of its facts, is an illusion of Anglo-American culture. Margaret Geller, well practiced in the observational branch of astrophysics, commented to Lightman:

You have to have a theoretical model. You can’t do science without prejudice…. When we designed the redshift survey to look for large structures, I had a prejudice. It turned out that my prejudice wasn’t right.

Dennis Sciama notes that models of the very early universe suggested by particle theory are a “mess,” not least because particle physicists, lacking sufficiently powerful accelerators, have not yet arrived at a grand unified theory “that we might have faith in.” The theorists note that, all the same, inflationary theory has for the first time enabled serious computational discussion of the very early universe. The scientific work being done on the later universe, combining theoretical modeling with computer simulations and observations, has come to involve strong interplay between theory and observation. The theory inspires measurements, the measurements challenge theory. The whole process, according to David Schramm, has made cosmology into something other than “just intellectual masturbation.”

In recent years, however, observations have been running way ahead of the ability of any theoretical model to account for them. Recently, for example, Margaret Geller and John Huchra discovered that a Great Wall of galaxies, stretching some 500 million light years across space, a structure so mammoth as to defy explanation of its formation by known processes in the billions of years that have passed since the Big Bang. More than one cosmologist thinks that further observational surprises may well be in store. Steven Weinberg himself says that “if it weren’t for the microwave background, I would begin to think real heresies might be worth pursuing right now.” Along with most physicists, cosmologists, and astrophysicists, Weinberg expects the standard Big Bang model to prevail, though probably in some revised form. (Theories are rarely proved to be altogether wrong, he comments, just incorrect in some domains and correct in others.) As for the newer inflationary theories of the very early universe, such as Guth’s, it is the general opinion that the inaccessibility of relevant evidence will keep the jury out for a long time.

No doubt cosmologists and astrophysicists have professional stakes in how the modeling of observations pans out, and data that undermine the theory have not always been rapidly welcomed. However, the data has tended to win a serious hearing and even acceptance, at least eventually; and it would seem to be the case that the cosmologists who may become emotionally involved in making an argument for one model or another usually have no emotional stake in the model itself—that is, in the nature of the universe as such. The galaxies, John Huchra notes, are there whether or not we can think of a good theory to account for their formation. What does it matter if the universe is flat, opened, closed, or if the expansion slows and things eventually die: “That’s the way it is,” Sandage says. “It doesn’t really matter whether I feel lonely about it or not.”

Contemporary cosmology has suggested much to search for in the heavens—ranging from missing matter to objects with larger and larger red shifts. An arsenal of new technologies such as digital detectors, image intensifiers, and orbiting telescopes has armed the searchers with unprecedented powers to look with efficiency and discernment farther out in the cosmos, further back in time. Cosmology will change to accommodate the new data. In its modern form, many of its practitioners emphasize in one way or another that it is a science, although a young one, and must not be confused with religion. What matters is what is really out there—like the great structures of the Great Wall. “Everything is always in trouble at the frontier.” Sandage recently remarked. “Any science that is not in this kind of trouble is dead.”¹⁷ Most cosmologists find excitement, and some, a sense of power in the task of probing the cosmos. Dennis Sciama told Lightman, “Roughly speaking, what I like to say is that the universe is enormous—it is much stronger than you are—and your only way of hitting back at it is to understand it.”